Convective blanket with discontinuous air flow guides and air flow patterns

ABSTRACT

A convective blanket has multiple sets of discontinuous bonding strips that bond or attach its upper layer to its lower layer to form a number of air flow guides within the blanket. There is at least one set of substantially parallel discontinuous strips proximate to the air input port of the blanket and another set of substantially parallel discontinuous strips remote from the air input port. For each set of in parallel discontinuous bond strips, the respective distal and proximal ends of each successive strips are aligned with the distal and proximal ends of a corresponding substantially in parallel strip to effect a cross channel so that air flowing along the air flow guide may escape to different sections of the blanket. To output the heated air from the blanket, respective single rows of successively spaced air holes are formed adjacent to and substantially along the length of the discontinuous bond strips that are located proximate to the air input port. For those sets of discontinuous bond strips that are remote from the air input port, there is provided adjacent to and substantially along the length of each of those strips multiple rows of successively spaced holes.

FIELD OF THE INVENTION

The present invention relates to inflatable convection blankets and more particularly to a blanket having a particular air flow configuration and air output patterns.

BACKGROUND OF THE INVENTION

To regulate the body temperature of a patient so as to prevent hypothermia to the patient in a medical environment, an inflatable convective blanket that provides a constant stream of warmed air is used. To provide uniform warmth to the patient, after heated air is input to the blanket for inflating the same, the flow pattern of the heated air, as well as the output of the warmed air from the blanket, needs to be regulated or guided in such a way as to eliminate, as much as possible, the difference in temperature of the warmed air output from the area of the blanket close to where the heated air is input to the blanket and the area of the blanket far away from where the heated air is input to the blanket.

One of the ways in which the prior art attempts to regulate the patterns of the flow of air in the blanket as well as to equalize the temperature of the heated air output from the various sections of a convection blanket is disclosed in U.S. Pat. No. 5,324,320, and its progeny patents U.S. Pat. Nos. 6,287,327 and 6,558,413. Those patents disclose a blanket that has a number of inflation cuffs, or tubes, longitudinally aligned along the length of the blanket. Passageways are provided between adjacent inflation cuffs, and staggered from cuff to cuff, so that each passageway would connect only adjacent cuffs and heated air can traverse between the cuffs. To equalize the temperature of the output air, in addition to having vent ports at the blanket, the apertures, or holes, wherethrough the heated air outputs from the blanket are designed into a pattern whereby the density of the apertures from the central portion of the blanket increase from the center portion of the blanket to the outer edges of the blanket. The configuration of the output air apertures of the above-discussed prior art blanket would work so long as the blanket is made up of a number of adjacent inflation cuffs, or tubes, longitudinally formed along the blanket. However, as convective blankets have now evolved into more than just inflatable self-erecting blankets which do not have the adjacent cuff configuration as the prior art blanket disclosed in the '320 patent, the flow pattern of the air in these non-self-erecting convective blankets need to be regulated so that the temperature gradient of the heated air output from such a blanket not vary substantially among the different sections of the blanket.

SUMMARY OF THE PRESENT INVENTION

The inflatable convection blanket of the instant invention is made of an upper air impermeable layer and a lower impermeable layer that are selectively bonded to each other substantially at their respective peripheries. A plurality of non-contiguous strips or seams whereby selective portions of the upper and lower layers away from the periphery are bonded to each other are formed at various sections of the blanket. Some of these strips are aligned, for example along the longitudinal axis of the blanket, to form a guide whereby air input to the blanket via an air input port flows. Two sets of such aligned strips that run parallel to each other form an air flow guide or a through channel in the blanket where the air input into the blanket is directed to flow in a given direction. Each set of the strips is made up of multiple non-contiguous strips, for example at least two. For each set of the multiple strips, the proximal and distal ends of each of the strips are in alignment with the proximal and distal ends, respectively, of a corresponding strip of another set of non-contiguous strips that make up the air flow guide channel. Accordingly, a cross channel is formed in the blanket structure for the air flow guide between the respective distal ends of the first of two successive non-contiguous strips and the respective proximal ends of the second of the two successive non-contiguous strips. Air being directed by the airflow guide can therefore escape from the airflow guide through such cross channel to other sections of the blanket.

To enable the heated air input to the blanket to exit from the blanket to thereby warm a patient placed on the blanket, the upper layer of the blanket, onto which the patient is placed, is manufactured to have a plurality of apertures, or holes, thereat for the heated air to escape. For the instant inventive blanket, the holes of the upper layer of the blanket are configured in the form of rows, with at least one row of equally spaced holes formed adjacent to each of the sets of the non-contiguous multiple strips that are located proximate to the air input port, where the heated air is input to the blanket. In order to equalize the temperature gradient for the warmed air output from the blanket, the air vent at the side, or far end, of the blanket remote or away from the air input port are configured in the form of at least two substantially parallel rows of successively spaced holes adjacent to each of the set of non-contiguous strips that form the air flow guide at that section of the blanket. With such configured holes and the air flow guides for the inventive blanket, it was found that a patient, for example an infant or child placed on the blanket, is bathed in an envelope of warm air which temperature gradient does not substantially vary across the surface of the upper layer.

A patient tends to lose a substantial amount of heat from his head. To remedy this shortcoming, the inventive blanket is further designed to have a warmed air output sealed section where the head of the patient tends to rest on, when the patient is placed on the blanket. To properly warm the head of the patient, the side of the sealed section closest to the air intake port is configured to have a row of successive holes that follows the curvature of that portion of the sealed section, whereas the side of the sealed section away from the air input port is configured to have at least two parallel rows of holes that follow the curvature of that portion of the sealed section, in order to equalize the warmth of the air bath at the sealed head section by varying the amount of warm air output at the head portion of the blanket.

The instant invention is therefore directed to an inflatable blanket that comprises an upper air impermeable layer with a lower air impermeable layer bonded thereto selectively along the periphery of the upper layer to form an inflatable structure, and a plurality of non-contiguous strips formed along the structure by the bonding of the upper and lower layers at selective areas of the structure. For the inventive blanket, there are at least two sets of multiple strips that run parallel to each other along the structure. Each set of the strips has at least two strips in longitudinal alignment with each other, with the two sets of parallel multiple strips forming a discontinuous air flow guide where the respective proximal and distal ends of each of the strips for the first of the two sets of strips being aligned with the respective proximal and distal ends of a corresponding strip for the second of the two sets of strips to form at least one cross channel along the air flow guide, so that some of the air flowing along the air flow guide may be directed to other sections of the structure by way of the cross channel.

Another aspect of inventive blanket is that an air input port is provided at the blanket where heated air under pressure is input to the blanket. Apertures or holes are formed in the upper layer of the blanket to output the input air, with respective rows of successively spaced holes being formed adjacent to the plurality of strips.

Yet another aspect of the present invention is that only one row of holes is provided adjacent to the multiple strips that form the air flow guide proximate to the air input port, and at least two substantially parallel rows of holes are provided adjacent a set of multiple strips that form the air flow guide at an area of the blanket that is far removed from the air input port.

A second embodiment of the instant inventive blanket includes an inflatable blanket that comprises a structure having an upper air impermeable layer bonded at selective sections of its periphery to a lower air impermeable layer, at least one air input port provided at the structure to enable air under pressure to be input to the structure, at least a first set of holes formed at the upper layer along one side of the structure proximate to the air input port to enable heated air input to the structure to exit, and at least a second set of holes separated by a given distance from the first set of holes formed on the upper layer along another side of the structure away from the air input port to enable heated air input to the structure to exit. The number of holes for the second set of holes is greater than the number of holes for the first set, with the number of holes for the second set being determined to be a number sufficiently greater than the number of holes for the first set to ensure that more heated air is output from the second set of holes than from the first set, so that a patient laying on the upper layer of the blanket would feel substantially the same level of warmth from the heated air output respectively from the first and second set of holes.

BRIEF DESCRIPTION OF THE FIGURES

The present invention will become apparent and the invention itself will be best understood with reference to the following description of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a plan view of the convective blanket of the instant invention;

FIG. 2 is an enlarged cross-sectional view taken along line 2-2 of FIG. 1; and

FIG. 3 is another view of the inventive blanket onto which a patient is placed.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIGS. 1 and 2, an exemplar convective blanket 2 of the instant invention is shown to have a first sheet or an upper layer 4 and a second sheet or lower layer 6. The upper layer 4 and the lower layer 6 are selectively bonded or attached, by means of adhesive or other means for example, at their respective peripheries 4 a and 6 a so that an inflatable structure is formed. The upper and lower layers 4, 6 are made from an air impermeable material, for example from woven materials conventionally known for the manufacture of the layers of convective blankets. Being air impermeable, fluid such as for example air could not escape from the blanket structure other than from apertures or holes formed on either the upper layer 4 or the lower layer 6.

As shown, there are two side extensions 6 b, 6 b′ for the lower layer 6 that extend beyond the side peripheries of upper layer 4. The extensions 6 b, 6 b′ are there for securing the blanket 4 to a bed or table, if necessary, as conventionally done. Although shown as extensions of lower layer 6, extensions 6 b and 6 b′ may in actuality be a separate layer or sheet that is bonded to lower layer 6. such additional sheet or layer is not shown in the figures for the sake of simplicity in the discussion of the inventive blanket.

In order to input air to inflate blanket 2, at least one air input port 8 is formed at blanket 2, for example at a junction of peripheries 4 a and 6 a of the upper layer 4 and the lower layer 6, respectively, as shown in FIG. 1. An optional air input port 8′ is also provided at the blanket and is used only in those circumstances where it is desirable that the heated air be input to the blanket close to the head of the patient. Heated air is input to blanket 2 for inflating the same by means of a conventional convective warmer, such as for example those sold by the assignee of the instant application. For conventional use, optional air input port 8′ is closed and air input port 8 is the primary source for inputting air to blanket 2.

To control the flow of air in blanket 2, the upper layer 4 and the lower layer 6 are bonded or attached together at a number of places in the form of either longitudinal strips or contoured strips that define a particular area of the blanket. The longitudinal strips are represented for example by strips 10 a-10 c and their corresponding substantially in parallel strips 12 a-12 c. These longitudinal strips comprise a number of non-contiguous strips in that strip 10 a does not extend to strip 10 b, and strip 10 b does not extend to strip 10 c. Alternatively, strips 10 a-10 c together may be considered as parts of a discontinuous air flow guide. The same is true with respect to strips 12 a, 12 b and 12 c. These discontinuous or non-contiguous strips are formed on blanket 2 in such a way that the respective distal and proximal ends of successive strips would form respective through passages, as designated for example by spaces 14 a and 14 b for strips 10 a and 10 b, respectively, that are substantially transverse to the longitudinal axis of the discontinuous air flow guides in blanket 2.

For discontinuous strips 12 a, 12 b and 12 c that lie substantially in parallel to strips 10 a, 10 b and 10 c, the distal end of strip 12 a, designated 12 a″, is separated from the proximal end 12 b′ of strip 12 b by a space 16 a while the distal end 12 b″ of strip 12 b is separated from the proximal end 12 c′ of strip 12 c by a space 16 b. These spaces 16 also form through passages between successive pairs of the discontinuous strips 12 a-12 c.

For the instant invention blanket, the substantially in parallel discontinuous strips 10 and 12 are formed on the blanket such that spaces 14 a and 16 a, and spaces 14 b and 16 b are in respective alignments so that respective cross channels are formed from the aligned spaces 14 a, 16 a and 14 b, 16 b of the parallel discontinuous strips 10 and 12.

Being substantially parallel, the two sets of discontinuous strips 10 and 12 form an air flow channel or guide to route air input from air input port 8 therealong. Additional air channels or air flow guides are formed by discontinuous strips 10 and 12 in blanket 2, i.e., the air channel between strips 10 and peripheries 4 a/6 a, and the air channel between strips 12 and the contoured strips 34 and 38. The air flows through these air channels established by the air flow guiding strips are represented by directional arrows 18 a-18 e. For the instant invention, the in parallel sets of discontinuous strips may therefore be considered to effect air flow guides.

Given that there are cross channels, as represented by the pairs of openings 14 a, 16 a and 14 b, 16 b, along the air flow guide created by the set of discontinuous strips 14 and 16, portions of the air flowing through the air guide channels, as represented by air flow arrows 18 a-18 c, are routed to other sections of the blanket.

A second pair of substantially parallel sets of discontinuous strips is represented by strips 20 a, 20 b and strips 22 a and 22 b. Strips 20 a and 20 b may be considered as portions of discontinuous strip 24 while strips 22 a and 22 b may be considered as portions of discontinuous strip 26. Strips 20 a and 20 b are separated by a through passage space 28 a while strip 20 b and strip 24 are separated by a through passage space 28 b. Likewise, strip 22 a is separated from strip 22 b by a through passage space 30 a while strip 22 b is separated from strip 26 by a through passage space 30 b. An additional contoured longitudinal strip 32 whereby the upper layer is bonded to the lower layer 6 is also provided on blanket 2.

A further set of strips, shown in FIG. 1 to be wider than the longitudinal strips discussed above, is provided in blanket 2 by the bonding of upper layer 4 to lower layer 6. The first such wider bonding strip is represented by bonded section 34 that seals area 36 of the blanket. A second wider section where upper layer 4 is bonded to lower layer 6 is represented by bonded section 38. A small longitudinal bonding strip 40 bonds upper layer 4 to lower layer 6 in the middle of the area bounded by wider strip 38. Although shown as wider strips, sections 36 and 38 may in actuality be defined by bond strips that have the same width as the earlier discussed strips. In other words, all bond strips for the exemplar blanket 2 shown in FIG. 1 may have the same width.

A cross section of blanket 2 where air passes is illustrated in FIG. 2. As shown, air is being guided by the air flow guides established by the in parallel discontinuous strips 20 a, 20 b, 24 and 22 a, 22 b and 26. As shown by the cross sectional illustration of FIG. 2, air may flow through cross channels 30 b and 28 b to intermix with the air flowing through the other channels that are represented by the air flows 18 e, 18 d and 18 c.

The heated air input to blanket 2 tends to cool down as it travels along the blanket. Accordingly, the areas of the blanket far removed or remote from the air input port, such as for example those areas of the blanket bounded by strips 20 a, 20 b, and 22 a and 22 b, tend to be inflated by air that has a lower temperature than the warmed air traversing in the area of the blanket bounded by strips 10 a, 10 b, 10 c and 12 a, 12 b and 12 c. Prior to the instant invention, to remedy this shortcoming, one type of convective blanket, as described in the aforenoted '320 patent, has an increasing number of holes for each of the longitudinal tubes that is further away from the center tube and closer towards both edges of the blanket. The number of holes for each longitudinal tube of the blanket therefore increases towards both side edges of the blanket, as represented for example by directional arrows 32 a and 32 b of FIG. 1. For this type of blanket, the air output is incrementally increased from the center of the blanket towards the edges of the blanket. The blanket disclosed in the '320 patent is made up of adjacent tubes and is meant to be used to cover a patient.

The instant inventive blanket, on the other hand, is a blanket onto which a patient is placed. Therefore, the air flow pattern for the instant blanket is substantially different from the prior art blanket, which does not have air flow guides made up of discontinuous strips with corresponding cross over channels effected by matching proximal and distal ends for directing air to different areas within the blanket.

To effect a blanket that outputs air with substantially the same degree of warmth at a portion of the blanket remote from the air input port as compared to a portion proximate to the air input port, the inventors found that only certain areas of the upper layer 4 along the bonded strips needed to have holes to allow the heated air to output or exit from the blanket. Thus, for the sets of discontinuous strips proximate to the air input port 8, such as for example strips 10 a-10 c and strips 12 a-12 c, there are formed on upper layer 4 a single row or set of successively spaced holes 39 adjacent substantially along the length of the set of discontinuous strips 10 a-10 c, and a second row or set of successively spaced holes 40 adjacent substantially along the length of the set of discontinuous strips 12 a-12 c, per shown in FIG. 1. Respective single rows or sets of holes 42, 44 and 46 are also provided substantially lengthwise along strips 24, 26, and the cross section of wider strip 38, respectively. All of those strips may be considered to be located proximate to air input port 8. Air substantially of a given temperature is output from the rows of holes 39, 40, 42, 44 and 46. Additional rows or sets of successively spaced holes 48 and 50 along the longitudinal sections of wider bond strip 38 are also provided. A single row or set of holes 52 is provided adjacent to the longitudinal portion of bonded strip 34.

To ensure that a patient placed on top of blanket 2 is evenly warmed thereby, a set of holes that is made up of at least two rows or family of holes (shown as parallel in FIG. 1) is formed adjacent to and substantially along the length of each set of the discontinuous bond strips remote from the air input port. For example, a set of two rows of successively spaced holes 54 is placed adjacent the set of discontinuous strips 20 a and 20 b, while another set of double rows of successively spaced holes 56 is placed adjacent the set of discontinuous bond strips 22 a and 22 b. There is moreover another set of two rows of successively spaced holes 58 placed adjacent a portion of the bonding strip 34 at one side of sealed section 36. By providing sets of multiple rows of holes adjacent to sets of discontinuous bond strips that are remote from the air input port, the amount of air output therefrom, for example from hole sets 54 and 56, is greater than the amount of air output from the sets of single hole rows, for example from rows 38, 40, 42, 44 and 46, so that the patient feels substantially the same amount of warmth at those disparate sections of the blanket. In other words, the patient is substantially enveloped by the same warm bath of heated air from substantially all areas of the blanket.

As the head of the patient tends to lose the most heat, by providing two substantially in parallel rows of successively spaced holes such as 58 adjacent to sealed section 36 where the head of the patient presumably is placed, the amount of heat loss from the head of the patient is reduced. Although two rows of holes are shown for each of sets 54, 56 and 58, it should be appreciated that more than two rows of holes may be formed adjacent to those discontinuous sets of bond strips when necessary to balance the amount of heated air output at those portions of the blanket that are remote from the air input port 8. The number of holes to be formed at those sections adjacent to the sets of discontinuous bond strips remote from the air input port needs to be a number that is sufficiently greater than the number of holes for the single rows of holes that are formed adjacent to the sets of discontinuous bond strips proximate to the air input port, so that the amount of heat provided to the patient at the various sections of the blanket does not vary substantially.

FIG. 3 shows a patient, in this instance an infant 60, placed on top of blanket 2, with his head resting on section 36 and his main body resting on the area of the blanket defined by bond strip 38 (FIG. 1), so that different amounts of air are directed to him from the plurality of rows of holes that are formed adjacent the different sets of discontinuous bond strips. As best shown in FIG. 2, when the blanket is inflated and air flows along the various air flow guides, upper layer 4 is inflated so that the double rows of holes, for example 54 and 56, would tend to point toward patient 60, shown in dotted box in FIG. 2, so that the warmed air is output directly toward the patient to establish a bath of warm air that envelops the patient. The directions of exemplar flows of the warm air towards the patient are indicated by directional arrows 62 a and 62 b. 

1. An inflatable blanket, comprising: an upper air impermeable layer having a periphery; a lower air impermeable layer bonded selectively along the periphery of said upper layer to form an inflatable structure; and a plurality of non-contiguous strips formed along said structure by the bonding of said upper and lower layers at selective areas of said structure; wherein at least two sets of multiple strips run substantially parallel to each other along said structure, each set of strips having at least two strips in longitudinal alignment with each other, said two sets of parallel multiple strips forming a discontinuous air flow guide, the respective proximal and distal ends of each of the strips for one of the two sets of strips being aligned with the respective proximal and distal ends of a corresponding strip for other of the two sets of strips to from at least one cross channel along said air flow guide so that some of the air flowing along said air flow guide is directed to other sections of said structure via said cross channel.
 2. Blanket of claim 1, further comprising: at least one port for inputting air under pressure to said structure for inflating said structure; and holes formed on said upper layer for outputting the input air, respective rows of said holes formed adjacent said plurality of strips, each row of holes formed substantially along a corresponding said set of multiple strips, the holes of said each row being successively spaced.
 3. Blanket of claim 1, further comprising: at least a first set of holes formed on said upper layer along one side of said blanket positioned relative to a port where air is input to said structure for inflating said structure; and at least a second set of holes formed on said upper layer along another side of said blanket far removed from said input port; wherein said first set being one row of successive holes and wherein said second set being at least two rows of successive holes.
 4. Blanket of claim 3, further comprising: at least one additional set of holes formed on said upper layer substantially in parallel to said second set, said additional set having the same number of rows of successive holes as said second set.
 5. Blanket of claim 1, wherein said blanket comprises at least one and other discontinuous air flow guides each with at least one cross channel therealong, further comprising: at least one port for inputting heated air under pressure to said structure for inflating said structure; respective first sets of holes formed at said upper layer along each set of strips that form said one discontinuous air flow guide, said respective first sets each having a predetermined number of holes for outputting the heated air from said upper layer; and respective second sets of holes formed at said upper layer along each set of strips that form said other discontinuous air flow guide, said second discontinuous air flow guide being far removed from said input port, the number of holes for each of said respective second sets of holes being selected to be sufficiently greater than said predetermined number to enable said each second set of holes to output heated air that has substantially the same warmth as the heated air output from each of said respective first sets of holes.
 6. Blanket of claim 5, wherein each of said first set of holes comprises a single row of holes and each of said second sets of holes comprises at least two rows of holes.
 7. Blanket of claim 1, further comprising: at least one port for inputting air under pressure to said structure for inflating said structure; and a sealed section at said structure whereon the head of a patient placed on top of said upper layer is positioned, one set of holes formed on said upper layer adjacent an area of said sealed section for outputting air directed to the head of the patient, and another set of holes formed on said upper layer adjacent another area of said sealed section further away from said port than said one set of holes for outputting air to the head of the patient from a different direction, said another set of holes having a greater number of holes than said first set f holes so that the heated air output from said another set of holes has substantially the same warmth as the heated air output from said one set of holes.
 8. An inflatable blanket, comprising: a structure having an upper air impermeable layer bonded at selective sections of its periphery to a lower air impermeable layer; at least one air input port provided at said structure; a plurality of non-contiguous strips formed along the body of said structure by the bonding of said upper and lower layers at selected areas of said structure; wherein at least two sets of multiple strips run parallel to each other along said structure, each set of strips having at least two strips in longitudinal alignment with each other, said two sets of parallel multiple strips forming one discontinuous air flow guide, the respective proximal and distal ends of each of the strips for one of the two sets of strips being aligned with the respective proximal and distal ends of a corresponding strip for other of the two sets of strips to from at least one cross channel along said air flow guide so that some of the air flowing along said air flow guide is directed to other sections of said structure via one said cross channel; and a plurality of holes at said upper layer to allow air in said structure to exit.
 9. Blanket of claim 8, wherein said plurality of holes comprise one row of successive holes provided at said upper layer adjacent substantially lengthwise to each of said two sets of parallel multiple strips.
 10. Blanket of claim 8, wherein said plurality of holes comprise at least two substantially parallel rows of holes formed at said upper layer adjacent substantially lengthwise along each of said two sets of parallel multiple strips.
 11. Blanket of claim 8, further comprising: another two sets of parallel multiple strips forming another discontinuous air flow guide, the respective proximal and distal ends of each of the strips for one of the two sets of strips being aligned with the respective proximal and distal ends of a corresponding strip for other of the two sets of strips to from at least another cross channel along said another air flow guide so that some of the air flowing along said another air flow guide is directed to other sections of said structure via said another cross channel; wherein one of said one and another discontinuous air flow guides is positioned proximate to said air input port and the other of said one and another discontinuous air flow guides is positioned far removed from said air input port.
 12. Blanket of claim 11, wherein said plurality of holes comprise one row of successive holes provided at said upper layer substantially along the length of each of the strips of said one discontinuous air flow guide proximate to said air input port and at least two substantially parallel rows of holes provided at said upper layer substantially along the length of each of the strips of said other discontinuous air flow guide positioned far removed from said air input port
 13. Blanket of claim 8, wherein some of said holes at said upper layer are formed to be substantially adjacent to said plurality of strips, the number of holes formed at said upper layer along the strips for said structure proximate to said air input port is less than the number of holes formed at said upper layer along the strips for said structure that are far removed from said input port.
 14. Blanket of claim 8, further comprising: a sealed section at said structure whereon the head of a patient placed on top of said upper layer is positioned, one row of holes formed on said upper layer adjacent an area of said sealed section for outputting air directed to the head of the patient, and at least two rows of holes formed on said upper layer adjacent another area of said sealed section further away from said port than said one row of holes for outputting air to the head of the patient from a different direction.
 15. An inflatable blanket, comprising: a structure having an upper air impermeable layer bonded at selective sections of its periphery to a lower air impermeable layer; at least one air input port provided at said structure to enable air under pressure to be input to said structure; at least a first set of holes formed on said upper layer along one side of said structure proximate to said air input port to enable heated air input to said structure to exit; and at least a second set of holes separated by a given distance from said first set of holes formed on said upper layer along another side of said structure away from said air input port to enable heated air input to said structure to exit; wherein there are a greater number of holes for said second set than for said first set, and wherein the number of holes for said second set is determined to be a number sufficiently greater than from said first set that would allow more heated air to be output from said second set of holes than said first set of holes so that a patient lying on said upper layer would feel substantially the same level of warmth from the heated air output from said first and second sets of holes.
 16. Blanket of claim 15, wherein said first set comprises one row of successive holes and said second set comprises at least two substantially parallel rows of successive holes.
 17. Blanket of claim 15, further comprising: a plurality of non-contiguous strips formed along said structure by the bonding of said upper and lower layers at selected areas of said structure; wherein said first set of holes comprises a row of successive holes formed at said upper layer along at least a first discontinuous strip located proximate to said air input port; and wherein said second set of holes comprises at least two substantially parallel rows of holes formed at said upper layer along at least a second discontinuous strip at a far side of said structure located away from said air input port.
 18. Blanket of claim 15, further comprising: a plurality of non-contiguous strips formed along said structure by the bonding of said upper and lower layers at selected areas of said structure; wherein some of said holes at said upper layer are formed to be substantially adjacent to said plurality of strips, the number of holes formed at said upper layer along the strips for said structure proximate to said air input port is less than the number of holes formed at said upper layer along the strips for said structure that are far removed from said input port.
 19. Blanket of claim 15, further comprising: a plurality of non-contiguous strips formed along said structure by the bonding of said upper and lower layers at selected areas of said structure; at least two sets of multiple strips run parallel to each other along said structure, each set of strips having at least two strips in longitudinal alignment with each other, said two sets of parallel multiple strips forming one discontinuous air flow guide, the respective proximal and distal ends of each of the strips for one of the two sets of strips being aligned with the respective proximal and distal ends of a corresponding strip for other of the two sets of strips to from at least one cross channel along said air flow guide so that some of the air flowing along said air flow guide is directed to other sections of said structure via one said cross channel; and another two sets of parallel multiple strips forming another discontinuous air flow guide, the respective proximal and distal ends of each of the strips for one of the two sets of strips being aligned with the respective proximal and distal ends of a corresponding strip for other of the two sets of strips to form at least another cross channel along said another air flow guide so that some of the air flowing along said another air flow guide is directed to other sections of said structure via said another cross channel; wherein one of said one and another discontinuous air flow guides is positioned proximate to said air input port and the other of said one and another discontinuous air flow guides is positioned far removed from said air input port.
 20. Blanket of claim 19, wherein said plurality of holes comprise one row of successive holes adjacent substantially lengthwise to each of said two sets of parallel multiple strips there are positioned proximate to said air input port and at least two substantially parallel rows of holes adjacent substantially lengthwise along each of said two sets of parallel multiple strips that are positioned far removed from said air input port. 